1. Technical Field
The present invention relates to a lens array with lenses arranged and a line head using the lens array.
2. Related Art
A line head for forming a latent image on a scanned surface of a photoconductor as a latent image carrier by scanning a light beam thereon is used, for example, as a light source of an electrophotographic printer as an image forming apparatus. An optical print head as the line head is provided with a head substrate mounting a plurality of light emitting element groups, and a lens array having lenses corresponding to the light emitting element groups.
As a method of manufacturing a lens array, there are known a method (see, e.g., JP-A-2005-276849 (pages 7 and 8, FIGS. 9 through 13)) of forming a mold using photolithography and electrocasting and then forming lenses on a glass substrate with light curing resin, a method (see, e.g., JP-A-2002-122706 (page 6, FIGS. 6 and 7)) of bonding a resin film provided with lenses on a glass substrate, and so on. Further, as a technology for a line head, there is provided a technology (see, e.g., JP-A-2008-36937 (pages 13 and 14, FIG. 12)) of using a lens array having lenses arranged two-dimensionally to image a plurality of light emitting elements corresponding to each of the lenses.
However, in the lens array used, for example, in an optical print head, since a number of lenses are arranged in the main-scanning direction, it is difficult to identify the position in the arrangement of the lane array of a specific lens among these lenses, in some cases. For example, when performing an inspection of checking whether or not the lenses have any blot or blemish in the manufacturing process of the lens array, there is a possibility of causing a problem that it is difficult to identify the position of the lens in the arrangement accurately and in a short period of time in response to detection of a defective lens.